This invention relates to a leveling device for an asphalt finisher, a base paver or the like.
As is well known in the art, for an asphalt finisher as shown in FIG. 1, while a vehicle body 1 is moving, bituminous material supplied from a hopper 2 is delivered to a spreading screw 4 by means of a bar feeder 3 and the asphalt compound is uniformly spread to the right and left by the spreading screw 4 and is then leveled by a screed 5.
In case where a conventional asphalt finisher as described above paves a relatively wide road, auxiliary screeds 6 are provided on either side of the screed 5 as shown in FIG. 2 to cover the entire width of the road. However, this method is disadvantageous in that mounting the auxiliary screeds requires a great deal of time, labor and skill.
In order to eliminate this disadvantage, a technique has been proposed in the art in which, as shown in FIG. 3, wideners 7 are provided on both sides of the screed 5 in such a manner that they are extendably and retractably provided with respect to the screed 5 by hydraulic cylinders. However, this technique is disadvantageous in that, since the wideners 7, unlike the screed 5, have no tamping function, the material leveled by the wideners 7 is different in finish from the material leveled by the screed 5.
In view of the foregoing, an object of the invention is to provide a leveling device by which the leveling width can be readily changed, leveling can be achieved with a uniform finish, and a crown can be provided at a desired position.